1. Field of the Invention
The present invention relates to an inverter driver integrated circuit, and more particularly, to an inverter driver integrated circuit including a sensor that can detect states, such as open lamps and overvoltage, by sensing a signal fed back from a lamp of a backlight unit.
2. Description of the Related Art
A plurality of cold cathode fluorescent lamps (CCFL) or light emitting diodes (LED) may be driven in parallel as lamps that ensure uniformity in the luminance of backlight units (BLUs) in display devices such as liquid crystal display (LCD) TVs.
In CCFLs, a fluorescent material is applied to the inner wall of a glass tube, electrodes are attached to both ends of the glass tube, and the glass tube is filled with a mixture gas having a pressure of tens of Torr and a predetermined amount of mercury. Such CCFLs are utilized in the lighting devices of LCD BLUs and the like because of their high luminance, high color rendering properties, low power consumption, and long useful life.
If any one of a plurality of lamps connected in parallel to each other is turned on before others, the resistance of the turned-on lamp may act like equivalent parallel resistance. In this case, a sufficient operating voltage is not applied to other lamps that are not turned on, so that those lamps remain turned off. Also, variations in overcurrent between lamps can cause a luminance imbalance. Therefore, it is considered important for BLU inverter driver integrated circuits to have protection circuit functions such as overvoltage protection (OVP), limited current circuit (LCC) and open lamp protection (OLP).
The demand for new concept one-chip inverter driver integrated circuits has arisen to achieve a reduction in the size of related art BLU inverters and to enhance cost competitiveness by minimizing the number of external components.